Campus Martius, republican SETH G. BERNARD The Campus Martius, the field consecrated to MARS, was the area of Rome just outside the city walls and within the curve of the TIBER River. This location, extramural but still close to the city’s center, gave the Campus a privileged polit- ical and religious position throughout Roman history. Its size alone was such that, when it was finally monumentalized in the Late Republic and Early Empire, the rest of the city seemed almost an appendage to it (Strabo 5.3.8). The Campus occupied that place “between the city and the Tiber,” as Livy and Dionysius explicitly tell us (Livy 2.5.2; Dion. Hal. Ant. Rom. 5.13.2; cf. Varro Ling. 5.28): that is, from the northwest foot of the Capitoline, extending northward along the Via Flaminia, up to the narrow pass between the river and the foot of the Pincian hill now still occupied by the Mausoleum of Augustus (Coarelli 1997: 3–10; Haselberger 2002: 74; Albers 2008: 13; contra Wiseman 1993: 200, who argues for a more defined area). This area was frequently inundated as the low-lyingCampus fell within the Tiber’s flood- plain. As many as three springs on the Pincian and Quirinal hills emptied across the Campus and into the Tiber (Funiciello et al. 1995: 179–203). Among them was the Petronian Stream (amnis Petronia) at the southeast, whose flow was incorporated into a covered drain in the Augustan period. A swampy area called the Goat’s Marsh (palus Caprae) origi- nally occupied the center of the Campus, a place associated with the death of Romulus (Muzzioli 1992: 189–208). This well-watered aspect made the area fertile agricultural land, and one ancient tradition held that King TARQUINIUS SUPERBUS owned and planted the Campus. Upon his expulsion, the area was reclaimed as public land and dedicated to Mars (Livy 2.5.2). An alternate tradition noted the presence of a cult to Mars already during Numa’s reign (Fest. 189; cf. Plut. Marc. 18); yet another etiology had the Roman people inherit the Campus from a Vestal, Gaia Taracia (Gell. 7.7). By various means, these stories reach the same ends: when the republic began, the Campus was public domain and dedicated to Mars. Quickly thereafter, the Campus took on sacral and communal aspects important to the young republic. Along the riverbank, at a place called Tarentum, Valerius Publicola celebrated the opening of the republic with the first ludi saeculares upon the altar to Dis and Proserpina (Coarelli 1997: 100–17). In 435 BCE, the censors laid out the Villa Publica in the Campus around the altar of Mars. Though over the years it accu- mulated a few auxiliary structures and porticoes, the Villa was mostly an unadorned public park with shady groves and benches (Varro Rust. 3.2). The Campus itself remained unencumbered by major architecture well into the Middle Republic. This openness made it particularly well suited for assemblies, both military and political. It was a place where soldiers in armor could muster without violating the sacred POMERIUM of the city, and it was associated with martial training from a very early period. It was here, too, that the people came together to vote in the comitia centuriata. In its archaic form, this assembly resembled the divisions of the Roman army and for this reason traditionally took place beyond the city’s pomerium (Taylor 1966: 5ff.). In addi- tion, the censors conducted the census in the Villa Publica. The historical relief on one side of the so-called Altar of Domitius Ahenobarbus (after 102 BCE; Kuttner 1993) depicts the taking of the census around the figure of Mars standing at his altar upon which the public lustrum and suovetaurilia marking the end of each census were performed. Thus, the Campus became a locus for civic action, and for a Roman citizen, the triplet “Campus Martius, Forum, Curia” represented the whole of Rome’s political topography (Cic. Cat. 2.1). The Encyclopedia of Ancient History, First Edition. Edited by Roger S. Bagnall, Kai Brodersen, Craige B. Champion, Andrew Erskine, and Sabine R. Huebner, print pages 1289–1291. © 2013 Blackwell Publishing Ltd. Published 2013 by Blackwell Publishing Ltd. DOI: 10.1002/9781444338386.wbeah20020 1